y - 2x = 3
x^2 + y^2 = 18
y = 3 + 2x
x^2 + (3 + 2x)^2 = 18
x^2 + (3 + 2x)(3 + 2x) = 18
x^2 + 9 + 12x + 4x^2 = 18
5x^2 + 12x + 9 = 18
5x^2 + 12x - 9 = 0
5x2 - 3x + 15x - 9
(x + 3)(5x - 3) = 0
X = -3, 3/5
y = 3 + 2x
y = 3 + 2(-3) y = 3 + 2(3/5)
y = -3 y = 4.2
(x,y) = (-3,-3), (0.6,4.2)
